209768823 has 12 divisors (see below), whose sum is σ = 330544968. Its totient is φ = 127132560.

The previous prime is 209768807. The next prime is 209768827. The reversal of 209768823 is 328867902.

It is not a de Polignac number, because 209768823 - 2⁴ = 209768807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209768827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1059340 + ... + 1059537.

It is an arithmetic number, because the mean of its divisors is an integer number (27545414).

Almost surely, 2^209768823 is an apocalyptic number.

209768823 is a deficient number, since it is larger than the sum of its proper divisors (120776145).

209768823 is a wasteful number, since it uses less digits than its factorization.

209768823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2118894 (or 2118891 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 209768823 is about 14483.3981855088. The cubic root of 209768823 is about 594.1740043913.

The spelling of 209768823 in words is "two hundred nine million, seven hundred sixty-eight thousand, eight hundred twenty-three".